Frustrated in my efforts to find a better-overclocking DDR4 kit than the one I’ve been using, I first found sets with slightly less capability, but twice the capacity. Then I discovered a kit with a similar rating, but a lower price. Finally, I looked at an alternative with similar overclocking headroom and more features. If my only purpose was to find faster RAM, I was not successful.
Maybe a lower price would sweeten the juice. And perhaps it’s time I stop thinking like a reviewer and start pretending it’s my money. I mean, how many overclockers really want to pay more for their RAM than they paid for their high-end motherboard? For many of us, overclocking has always been about value!
With Kingston’s almost-value-priced DDR4-3000 barely able to overclock past its rating, I began to wonder if a lower-rated part from an overclocking-focused brand might be a little more flexible. Corsair’s Vengeance LPX looks the part, particularly in its CMK16GX4M4A2666C15R (that last R is for Red) limited edition. It’s cheaper than Kingston’s parts, and if it can match them in an overclock, we just might find a top enthusiast value.
Encouragement for this value-finding mission is spotted in the Vengeance LPX XMP registers, where we see that its DDR4-2666 rating comes at a mere 1.2V. Corsair even adds an XMP-2800 entry, just to act as a starting point for real overclocking. The rated timings aren’t great though.
Fortunately, as the DDR4-2800 XMP value shows, these are designed for overclocking. We’re putting them up against the previously-reviewed HyperX Predator today, while the reference kit that G.Skill sent serves its purpose by setting the high mark.
Something we noticed in our previous DDR4-2800 review was our motherboard’s tendency to use the CPU’s 1.25x BCLK strap whenever fast memory is used. One might expect the same board to use the default 100MHz strap whenever an Intel-enabled data rate is available, but the motherboard simply ignored its 26.66x data rate ratio (which is actually a 10x memory multiplier on a 4/3 internal memory controller ratio using a 100MHz base clock and DDR). The default DDR4-2133 ratio was instead applied to a 125MHz BCLK to match the rated DDR4-2666.
I could have proceeded from here using a 32x CPU ratio to maintain my previous 4GHz CPU test frequency, but I decided to forgo the 1.25x ratio in light of its instability on several of our previously-tested boards. The DDR4-2666 ratio for a 100MHz BCLK is available on every enthusiast-class X99 motherboard we’ve tested.
Full details of my DDR4 test platform are available in my previous review.